This invention relates to means to compensate the output from a fluid meter (not disclosed herein) in a pipeline for variations in pressure and temperature of the fluid being metered. When it is not desired to compensate the output of the meter for pressure and temperature variations, the output from the meter is connected directly to a counter, register or other readout device. However, since variations in the pressure and temperature affect the energy content of the fluid it is often desirable to compensate the readout from the meter to reflect such variations in pressure and temperature. This is usually done by providing a variable ratio drive transmission between the meter and the readout counter with means to vary the output of the variable ratio transmission in accordance with both pressure and temperature variations. Such devices are known in the art as integrators and typical of the prior art are the integrators shown in the U.S. Patent to Kugler U.S. Pat. No. 3,538,766 and the U.S. Patent to Blakeslee et al U.S. Pat. No. 3,895,531, the presure invention being an improvement to the devices shown in these U.S. patents. The integrators shown therein employ ring members to transfer the drive between cylindrical drive elements and cone elements in the Blakeslee et al patent and from cylindrical elements to a disc element in the Kugler patent. In order to prevent slippage between the ring members and the other elements of the drive it is necessary that the radial coupling force between the ring elements and the other elements be relatively high which leads to comparatively low drive efficiency, excessive wear and reduced accuracy after extended periods of use. Also such prior art integrators require frequent maintenance and are relatively difficult to calibrate.
Integrators such as those described herein are used in fluid metering applications primarily gas metering, and provide a totallized readout of the volume of fluid which passes at varying flow rates through a meter over a given period of time. The American Gas Association specification B-109 requires that integrators for such applications perform with a minimum accuracy of .+-.99.25% over a full range of pressures and temperature which the integrators are required to operate. It is therefore extremely important that the variable speed drives employed in such integrators have extremely high transmission efficiencies over their full operating range for extended periods of time and not be affected by changes in environment. Thus the engagement between the driving and driven members of such drives must be such that the force biasing the members together be held to a minimum while allowing virtually no slip between the members over the entire range of speeds, and speed change ratios which the integrator is designed to operate. This accuracy and transmission efficiency must not be subject to deterioration over extended periods of time and thus the operative members must not be subject to significant wear and must be made of materials which are chemically stable.